Acyloxyneopentyl and acyloxycyclobutane phosphate partial esters



United States Patent 3,153,030 ACYLOXYNEOPENTYL AND ACYLQXYCYCLO- BUTANEPHQSPHATE PARTKAL ESTERS John R. Caldwell, Kingsport, Tenn, assignor toEastman Kodak Company, Rochester, N.Y., a corporation of New Jersey NoDrawing. Filed Jan. 31, 1961, Ser. No. 85,969 3 Claims. (Cl. 26e 4s1This invention relates to novel phosphate and phosphite esters and amethod of preparation thereof. More particularly, the invention isconcerned with the preparation of esters derived from alicyclic hydroxycompounds.

Phosphate esters of glycerine and glycols are relatively unstable towardhydrolysis and thermal decomposition, making them generally unsuitablefor such uses as wetting agents, extreme pressure lubricants, additivesfor increasing the lubricity of synthetic lubricants, surfactants,emulsifying agents, degreasing agents and plasticizers and the like.After extended investigation I have found that by treating certainneopentyl alcohols with suitable phosphorus derivatives, neutral andacidic esters are formed which are highly stable toward both hydrolysisand thermal decomposition and accordingly are appropriate for theaforementioned uses.

Therefore, it is an object of the present invention to provide novelphosphate and phosphite esters having a high degree of stability towardhydrolysis and thermal decomposition. Another object of this inventionis to provide novel phosphorus esters that are highly resistant todecomposition to phosphoric and phosphorous acids. A further object isto provide esters having a highly hindered or blocked structure whichgreatly reduces their hydrolysis rate. Still another object of thepresent in vention is to rovide a novel s nthetic rubber sheetincontaining phosphorus esters. A still further object of this inventionis to provide a method for the preparation of the aforementionedphosphate and phosphite esters.

In accordance with my invention, broadly, neopentyl alcohols are reactedwith phosphorus derivatives to give novel phosphorus esters containing aneopentyl or hindered structure which imparts thereto improvedhydrolytic and thermal stability. The esters provided by my inventionmay be characterized by one of the following formulas, or they mayconsist of a mixture' of more than one ester coming within the scope ofthese formulas.

(R-( i0Y0)mi"(Z)n or (R( i0Y0)mP(0H).. In these formulas R may be astraight or branched chain alkyl radical containing from 1 to 20 carbonatoms, a cyclic alkyl, aryl, or alkylene group. Y represents eitherwherein R and R are alkyl radicals having from 1 to 4 carbon atoms, andZ is either --OH or In the latter formula, R and R may be the same ordif 3,353fi3d Patented Get. 13, I964 ferentfbut are either a hydrogenatom, an alkyl radical having from 1 to '6 carbon atoms, or a'phenylradical. m is an integer from 1 to 2, and n is a number such that thesum of n and m is 3. In general, the method for producing the novelphosphorus esters of the above configuration consists of reacting anester-alcohol of the formula formulas:

-P 0 on v P 0 POCI PCl C H NHPOCl ClPO [N(C H and ClPO(NHC H Thereaction may be conveniently carried out at room temperature in anappropriate organic solvent such as ethylene dichloride, dioxane,toluene, or ether and the reaction may be catalyzed by pyridine,triethylamine, or other appropriate catalyst, depending upon whether itis desired to form a neutral or acidic phosphite or phosphate or aphosphonate. The reaction requires from about 1 to about 12 hours forcompletion. The esters or ester-alcohols to be reactedwiththeappropriate phosphorus-containing compound may be convenie'ntly preparedby heating 1 molecular proportion of a carboxylic acid with 3 to '5molecular proportions of the' or amines. When it is desired to prepareneutral phosphates, the alcohols may be reacted witl1 POCl in the r,

Neutral presence of v a tertiary, amine or other base. phosphites havingthe structure (RO.) POH may be made by treating the alcohols with PCl inthe'absence of a base, ,whereas .phosphite's having the structure (RO Pare obtained if a base is used. By the same general method ofpreparation, it is possible to prepare phos phonates and derivativescontaining a phosphorus-nitrogen linkage such as V Il 0.-

where the nitrogen may contain one or more alkyl' or aryl substituentsor hydrogen. An extreme pressure lubricant may be prepared from thephosphate ester products by mixing them with an" appropriate alcoholsuch as I lauryl and mineral oil. -Also,'theymay be added as aplasticizer to butadiene-acrylonitrile synthetic rubber and I the'rubberthereafter extruded as thinsheets highly resist- 1 ant to hydrolysis andthermal decomposition.

The invention is examples: 3

' Example I;

One molecular proportion of single pressed'stearic acid furtherillustrated in the following i w was heated at 210-220 C. with 4molecular proportions of 2,2-dimethyl-l,3-propanediol until the acidnumber was approximately 1.0 or less. A trace of titanium isopropoxidewas used as catalyst. The mixture was then washed several times with hotwater to remove excess glycol and dried by heating in vacuum at 70-80 C.The product was a wax that melted at 40-45 C. One molecular proportionof P 0 was added with stirring and cool ing to 4 molecular proportionsof the glycol monostearate dissolved in ethylene dichloride. Theethylene dichloride was removed by vacuum distillation at 50-60 C. Theproduct was a wax that consisted of a mixture of monoand dialkylphosphates having the structures:

The product was useful as an additive for extreme pressure lubricants.The alkali metal and amine salts, when used as surfactants, showedexcellent resistance to hydrolysis.

The above product was neutralized with triamylamine. The resulting saltproved useful as an additive for synthetic lubricants. Two parts of thesalt were added to 98 parts of dioctyl azelate. The ester showedimproved lubricating action, especially under heavy loads.

The sodium salt was demonstrated to be of particular value as asurfactant and emulsifying agent for use in strongly alkaline solutions.For example, an emulsion was prepared by mixing g. of the sodium salt,85 g. of kerosene, 10 g. of sodium hydroxide and 500 cc. of water in ahigh speed colloid mill. The emulsion was useful as a degreasing agent.Although the emulsion had a pH of 12-13, the phosphate ester showed noevidence of hydrolysis, even after standing 48 hours.

Example 11 One molecular proportion of technical lauric acid was heatedwith 4 molecular proportions of 2,2-dimethyl-1,3- propanediol at ZOO-210C. until an acid number of less than 1.0 was obtained. A trace oftitanium isopropoxide was used as catalyst. The excess glycol wasremoved by washing with hot water. The product was an oil. Threemolecular proportions of the glycol monolaurate was treated with P001 inthe presence of pyridine to give The product was a viscous oil. It wasused as a plasticizer and as a synthetic lubricant and exhibited a highdegree of thermal stability and resistance to hydrolysis. It showedutility as an additive for petroleum oils and ester-type lubricants.

Fifteen parts of the above phosphate ester were mixed with 85 parts ofbutadiene-acrylonitrile synthetic rubber as a plasticizer. The rubberwas extruded as thin sheets. Exposure of the sheets to 5% sodiumhydroxide solution for 2 weeks caused no appreciable hydrolysis of theplasticizer.

Example 111 One molecular proportion of isobutyric anhydride was heatedat 90l00 C. for 12 hours with 5 molecular proportions of2-methyl-2ethyl-propane1,3-diol. Pyridine was used as a catalyst. Thebutyric acid and excess glycol were removed by washing with hot water.The product was dried by heating in vacuum at 70-80 C. Two molecularproportions of the glycol mono-isobutyrate were treated with onemolecular proportion of P 0 The 4 product, a mixture of acid phosphates,was used as an ore flotation agent.

Example IV The mono-isobutyrate of 2,2,4,4-tetramethyl-1,3-cyclobutanediol was treated with PCl in the presence of base to give thetrialkyl phosphite. The product was used efficiently as a plasticizerand lubricating oil additive.

Example V The rnonohexanoate of 2,2-diethyl-1,3-propanediol was treatedwith dichlorophenylphosphine oxide in the presence of pyridine to giveThe phosphate ester was used as the lubricant in a gear box that wasoperated at a temperature of -160 C. and was exposed to moisture. Thelubricant showed no appreciable hydrolysis or decomposition after 4weeks of use.

Example VI The mono-isobutyrate of2,2,4,4-tetramethy1-l,3-cyclobutanediol was treated with C H NHPOCl inthe presence of triethylamine to give CH CH Cfi CH 2 The compoundexhibited good plasticizer activity.

Example VII One molecular proportion of technical palmitic acid and 4molecular proportions of 2,2,4,4-tetramethyl-1,3- cyclobutanediol wereheated at ZOO-210 C. for 3-4 hours, using a trace of dibutyltindiacetate as catalyst. The acid number was less than 2. The mixture wasthen washed with hot water to remove excess glycol and dried by heatingin vacuum at 70-80. The ester was a wax that melted at 40-50" C. Theproduct was principally the monopalmitate of2,2,4,4-tetramethyl-1,3-cyclobutanediol. 382 g. (1.0 mole) of thismonopalmitate ester was dissolved in 1000 ml. of ethylene dichloride.The solution was stirred at 20-30, and 35.5 g. (0.25 mole) of P 0 wereadded in small portions during a period of 1 hour. The mixture was thenstirred at 20-30 for 12 hours to complete the reaction. The product wasa wax that consisted of a mixture of monoand diallryl phosphates havingthe structures.

CH CH3 t r l and CQCH:

Part of the product was neutralized to a pH of 8.0-8.5 by the additionof aqueous sodium carbonate solution to the ethylene dichloridesolution. The salt was isolated by evaporating the ethylene dichlorideand water. The product was a wax. It gave a soapy dispersion in waterand was a powerful wetting agent. The utility of the product wasdemonstrated by adding it to a strongly alkaline solution as a wettingagent. In this use substantially no hydrolysis of the ester resulted.

A second part of the product was neutralized to a pH of 7.0-7.5 by theaddition of N,N-diethylcyclohexylamine.

The salt was isolated by evaporating the ethylene dichloride. This saltwas especially valuable as an additive for increasing the lubricity ofpetroleum oils for use in extreme pressure applications. An extremepressure lubricant was prepared by mixing 2 parts of the phosphate saltand 5 parts of technical lauryl alcohol with 93 parts of mineral oil.Additional utility was demonstrated by adding 3 parts of the salt to 97parts of 2,2-dimethyl-1,3 propanediol dipelargonate. The lubricity ofthe synthetic lubricant, especially under heavy load, was greatlyincreased.

Example VIII In this example two esters of the present invention werecompared with a prior art ester as to hydrolytic stability. Two grams ofthe mixed monoand dialkyl phosphate product of Example I and 2 grams ofsodium hydroxide were dissolved in 50 cc. of water and the solutionreiluxed for 6 hours. An aliquot portion of the solution was titratedwith standard HCl solution, and the unreacted sodium hydroxide wasdetermined. By this determination, it was calculated that the ester was-24% hydrolyzed. Two g. of the salt prepared by the neutralization ofthe mixture of monoand dialkyl phosphates of Example VII were boiled inaqueous sodium hydroxide. Less than 5% hydrolysis resulted. As comparedto the hydrolytic stability of the preceding two products, 2 g. ofglycerine monolaurate phosphate treated in the same manner showed 80 to90% hydrolysis.

Example IX In this example the thermal stability of 2 additional estersof the present invention were compared with the thermal-stability of atypical prior art ester. 100 g. of the combination of Example II wereheated at 575 F. in a stream of pure nitrogen. Samples were taken atintervals and titrated for acidity. The rate of acid formation was foundto be 0.08% per hour. The compound of Example VI was treated in asimilar manner and showed a decomposition rate of 0.06% per hour. Thephosphate of diethylene glycol monolaurate, on the other hand, uponbeing similarly treated exhibited a decomposition rate greater than 1.0%per hour.

Example X The monobenzoate of2,2-diethyl-4,4-dimethyl-l,3-cyclobutanediol was treated with ClPo[N(C Hin pyridine to make CH3 CH3 CzH5 0 115 The compound proved useful as aplasticizer and as an additive for extreme pressure lubricants.

Example XI The monobenzoate of 2,2-dimethyl-1,3-prop-anedio1 was treatedwith ClPO(NHC H in the presence of pyridine to form This compound washighly satisfactory as a plasticizer and as an additive for extremepressure lubricants.

It can already be seen from the preceding description and examples thatthe novel phosphate and phosphite esters of this invention exhibit asurprisingly high degree of stability against boththermal-degradationand hydrolysis and are accordingly highly useful assurfactants, plasticizers, degreasing agents, emulsifiers, and the like.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

I claim:

1. Esters comprising compounds and a mixture of compounds having aformula selected from the group consisting of II Ii l Ro-o Y-0' ,..P(z'and rt-o-0Yo mr (01r wherein R is selectedfrom the group consisting ofstraight and branched chain alkyl having from 1 to 20 carbon atoms,cyclic alkyl containing 6 to 10 carbon atoms and phenyl, Y is selectedfrom the group consisting of wherein R and R are alkyl having from 1 to6 carbon atoms, Z is selected from the group consisting of -OH andwherein R and R are selected from the group consisting of a hydrogenatom, alkyl having from 1 to 6 carbon atoms, and phenyl, m is an integerfrom 1 to 2 and n equals 3m'.

2. A phosphorus ester having a formula selected from the groupconsisting of the group consisting of a mixture of and a mixture of L CHCH 2 and orra CH3 Ci5HsiCO OPO(OH);

CH3 CH3 (References on following page) References Cited in the file ofthis patent UNITED STATES PATENTS Caulfield Nov. 1, Harris Jan. 7,Rozenbroek Sept. 19, McDermott Mar. 10, Buchner et al. May 11, Harman etal. Nov. 29, Morris et a1. Dec. 6, Spivack Jan. 29,

1. ESTERS COMPRISING COMPOUNDS AND A MIXTURE OF COMPOUNDS HAVING AFORMULA SELECTED FROM THE GROUP CONSISTING OF